In many industries a dust-like waste product known as fines is a by-product of a production process. An example of an industry producing fines as waste material is cat box filler manufacturing, wherein raw clay is treated and calcined to form an absorbent compound for use in cat boxes. Clay fines, which are the undersize particles that are unsuitable for the end product desired, are obtained both from the initial screening of the raw clay material and from the final screening of the end product before packaging for marketing. Thus, the fines include both calcined and non-calcined clay particles, and may range in size from just under the desired particle size to very fine dust or powder-like material. The clay fines may be generated during any of the steps of the manufacturing process, including granulation or crushing, drying, transporting, or any other operation wherein heat and/or stress operate to separate the material into separate and distinct groups. In the past the clay fines constituted waste and were disposed of, often by mixing the fines with water and discharging the mixture into slurry ponds or the like. Adequate disposal areas had to be provided near each manufacturing plant to handle the clay fines waste material, and the environment impact of the chosen fines handling method and disposal procedure had to be carefully analyzed and controlled. The amount of clay fines waste material can be substantial in some processes, with the effect being a significant economic burden on the overall manufacturing process to handle and dispose of the fines, thereby requiring an increase in the sale price of the marketed product to cover the cost of fines disposal. It is clear that the planning for and handling of clay fines has been totally an item of expense in industries such as cat box filler manufacturing, with no income generated from the fines material. Hence, any use for clay fines, and particularly a use adaptable to a variety of readily marketable products, will provide significant economic advantages within the industry.
Another waste product common in the United States is fly ash, which is a pozzolana composed of silicates and various oxides and which occurs as a waste product from coal combustion. Millions of tons of fly ash are created annually by factories, electric power generating stations and the like, and it has been estimated that only about 25% of all fly ash waste material is used in some form, usually as a component for road construction or in cement, with the remaining 75% constituting waste which has to be disposed of. The disposal of fly ash has created problems in some locations, requiring trucking of the ash for long distances to suitable disposal sites. Since coal is projected as being the fossil fuel with the longest future availablility, the production of fly ash will continue for many years to come and is likely to increase in amount. Since coal is used throughout the country, the availability of fly ash is fairly universal, and a suitable use for this widely available waste product will have a significant economic impact in the coal use area, as well as relieve a very significant disposal problem.
Other waste products from manufacturing processes which have caused economic burdens on their respective industries and have created disposal problems include peanut shells, sawdust and paper sludge, which is a combination of broken down cellulose fiber, pulp treating chemicals, clay, and water. A suitable process for using these and other herefore substantially non-usable waste products will provide manufacturing cost efficiency in the industries producing the waste, will open new fields of manufacture, and will eliminate the need for disposal sites near each operating plant.